Sensing toxic gas molecules is crucial for environmental monitoring and human safety. In this spin-polarized DFT study, we introduce BCN nanocage, a hybrid analogue of C₂₀ nanocage, for sensing Cl2, COCl2, H2S, and NH3 gas molecules. BCN is functionalized with a series of metal adatoms (Li, Be, Al, Si, P, Sc, Ti, V, Mn, Fe, Ni, and Cu), chosen for their diverse electronic configurations and potential to interact strongly with the substrate. Among these, only the Li-, Al-, Sc-, Fe-, and Cu-decorated BCN complexes were found to be thermodynamically stable and energetically favourable. Sc exhibits the strongest binding with the nanocage, followed by Fe, Al, Li, and Cu, due to bond formation and significant charge transfer from adatoms to the nanocage. Among the studied candidates, BCNCu emerges as the most promising for Cl2 sensing under dry conditions, exhibiting an adsorption energy of 0.66 eV, a recovery time of 0.02s, and a -37.16% band gap variation. Compared with previously reported nanocage-based sensors, BCNCu demonstrates a balanced combination of suitable adsorption energy, rapid recovery time, and appreciable sensitivity, highlighting its potential for efficient Cl2 detection under dry conditions. However, its sensing performance is influenced by humidity, indicating that BCNCu operates more effectively under dry conditions than in humid atmospheres. AIMD simulations and vibrational spectra analysis confirm the thermal stability of the substrate at 400 K and its dynamical stability. This study advances the field by establishing BCNCu as a promising Cl2 sensor while highlighting its limitations in humid environments, offering valuable insights for experimental fabrication and real-world applications.
In this study, quantum dots with Au/CdSe complex cores composed of Au as a metal base were synthesized, syrup was prepared, and coated on natural simulated LED unit modules, and the optical properties of traffic signs using them were investigated, and the following conclusions were obtained. The nanoparticles synthesized at 260°C and 280°C grew into irregular shapes with PL wavelengths of 624-627㎛, half-widths of 35㎛, PL-QY ratios of 55-61%, and grain diameters of 5-7㎛. The quantum dot syrup was applied to the LED unit module to produce a traffic sign composed of 4CL unit modules, and the luminance of 179 ㏅/㎡, insulation resistance of 10,000㏁, and insulation withstand of 500V were achieved, meeting the performance and specifications of the standard guidelines for luminescent traffic safety signs. The surface temperature of the unit module laminated with 4CL resin is 24~25℃, which shows a stable heat distribution, confirming that it can be applied as a sign using unit modules.
In this study, the surface characteristics—including roughness, oxide layer thickness, and composition—of the electropolished layer on STS316L steel tubes subjected to double melting via the VIM/VAR process were investigated after exposure to Cl2 gas. The tubes were exposed to Cl2 gas for 1 to 13 d to simulate semiconductor conditions. Surface roughness increased with Cl2 exposure time, showing values of 0.01, 0.04, 0.04 and 0.03 μm after 0, 1, 5 and 9 d, respectively. At the same time, the oxide layer thickness on EPed STS316L, which was initially 8.2 nm, decreased to 3.18, 2.58 after 1, 5 d of Cl2 exposure, approaching the initial thickness of 2.38 nm observed on non-EPed STS316L. After 9 d, the thickness further decreased to 0.51 nm, with no significant change was observed thereafter. Before Cl2 exposure, the CrO/FeO ratio was 2.26. After 1, 5, and 9 d of exposure, the ratio decreased to 2.06, 1.75, and 1.27, respectively. In addition, the penetration depth of Cl into the oxide layer increased with longer exposure time. These results suggest that the formation of chromium chlorides led to the breakdown of the stable Cr2O3 layer.
In this paper, poly(glycolic acid–co-DL–lactic acid) (PGDLLA)/poly(ɛ-caprolactone) (PCL) incompatible nanocomposites were combined with multiscale modeling (MSM) in a ratio of 80/20. Since the behavior and mechanical properties of blends depend significantly on the interphase region, the compatibilizer poly(l,l-lactic acid–co-ɛ-caprolactone) (P(lLA-co-ɛ-CL)) was used to improve compatibility and graphene oxide (GO) was used to increase the interphase strength of PGDLLA matrix/PCL. This work was done by mixing solvent to achieve the optimum disperse of GO in the matrix. The investigation of interfacial phenomenon by the theoretical interfacial models is important. Under the assumption of constant modulus and elastic deformation in the zero interface region, the predictions in this region are more unreliable when the calculations of experimental mechanical properties are analyzed in detail. In this study, PGDLLA/P(lLA-co-ɛ-CL)/PCL compounds were compared with the MSM approach to predict the plastic deformation in the stress–strain behavior. In contrast to the hypothesis that a simple look at the interphase area in nanocomposites, a finite element code is proposed to evaluate the efficiency of the interphase area. Both experimental results and FEM analysis showed that Young’s modulus increases by incorporating GO into GO/PGDLLA/P(lLA-co-ɛ-CL)/PCL nanocomposites; the amount of increase for incorporating 1 phr GO is about 61%.
목적: 본 연구는 투명 콘택트렌즈와 멀티포컬 콘택트렌즈를 각각 착용하여 원·근거리에서 시력을 측정하였을 때 가입도가 처방된 멀티포컬 콘택트렌즈가 양안시기능에 미치는 영향을 알아 보고자 하였다.
방법: 전신질환이 없고 양안시이상에 문제가 없으며 난시량이 –1.00D 이하인 남·여 15명( 평균연령 21.6±1.5세)을 대상하였다. 자각식굴절검사를 통해 완전교정 상태를 검출하여 일반콘택트렌즈와 멀티포컬콘택트렌즈를 각각 착용시킨 상태와 수정된 모노비전 방법으로 착용시킨 상태로 구분하여 각각 원거리 3m에서 세막대심도지각계를 이용한 심시력 검사와 근거리 40cm에서 입체시(titumus fly) 검사를 실시하였다.
결과: 일반콘택트렌즈를 착용한 상태에서 근거리 입체시력은 79.8±47.5sec이었고 멀티포컬 콘택트렌즈 착용 시 입체시력은 82.8±48.9sec이었으며 수정된 모노비전 착용 시 입체시력은 78.3±36.4sec로 멀티포컬콘택트렌즈 착용 시 입체시력이 떨어지는 것을 알 수 있었다. 그리고 심시력은 일반콘택트렌즈에서 9.58±4.67sec, 멀티포컬콘택트렌즈에서 19.9±12.72sec, 수정된 모노비전에서 6.45±6.32sec로 멀티포컬콘택트렌즈를 착용하였을 때 심시력이 저하된 것 을 알 수 있었다.
결론: 일반콘택트렌즈를 착용하였을 때보다 멀티포컬콘택트렌즈를 착용하였을 때 심시력과 입체시력이 감소하는 것을 알 수 있었다.
The purpose of this study was to measure concentrations of K+, Na+, Cl- by ionometer with check salt strip, simple salimeter and Ion-selective electrode (ISE) and compare the results of each mensuration; furthermore, the possibility of inferring the Na+ concentration from Cl- concentration of urine and the impact of K+ on the concentration of each ion was examined. The results showed that ISE determined Na+ and Cl- concentrations in the urine are highly interrelated (R=0.9039); in addition, concentrations of Cl-, measured with strip and ISE from urine are highly interrelated (R=0.9338). The concentration of Na+ in urine, inferred by measuring Cl- concentration with strip, has a high relationship (R=0.8580) with the concentration of Na+ in urine, measured by ISE. The results of our study will increase awareness of Na+ intake and the utility of check salt strip, as well as the possibility of inferred Na+ concentration from measures of Cl- concentration as a screening test for reducing sodium intake.
In spray pyrolysis, the effects of the preparation temperature, flow rate of the carrier gas and concentration of the spray solution on characteristics such as the morphology, size, and emission intensity of Ca8Mg(SiO4)4Cl2:Eu2+ phosphor powders under long-wavelength ultraviolet light were investigated. The phosphor powders obtained post-treatment had a range of micron sizes with regular morphologies. However, the composition, crystal structure and photoluminescence intensity of the phosphor powders were affected by the preparation conditions of the precursor powders. The Ca8Mg(SiO4)4Cl2:Eu2+ phosphor powders prepared at temperatures that were lower and higher than 700˚C had low photoluminescence intensities due to deficiencies related to the of Cl component. The phosphor powders with the deficient Cl component had impurity peaks of Ca2SiO4. The optimum flow rates of the carrier gas in the preparation of the Ca8Mg(SiO4)4Cl2:Eu2+ phosphor powders with high photoluminescence intensities and regular morphologies were between 40 and 60 l/minute. Phosphor powders prepared from a spray solution above 0.5 M had regular morphologies and high photoluminescence intensities.
본 연구는 토양에의 고농도 Na 및 Cl 염류처리가 토마토의 생육과 무기성분 흡수, 광합성 속도 및 수분 포텐셜에 미치는 효과를 검토코자 수행되었다. 초장, 생체중, 건물중 등 생육은 대조구에 비해 모든 염 처리구에서 억제되었으나, 토양의 pH와 EC와는 관계가 없었다. 토마토의 생육억제 효과는 Na계열에서는 Cl, SO4, CO3, PO4, NO3 순으로, 그리고 Cl 계열에서는 Na, K, Mg, NH4, Ca순으로 컸으며, Na 계열이 Cl 계열보다 컸다. 토마토의 수량은 대조구보다 모든 염 처리구에서 30%~10%적었으며,특히 NaCl처리구에서 더욱 적었다. 엽록소 함량, 광합성 속도, 기공전도도는 대조구에 비해 염 처리구에서 낮았다. 무기양분 함량은 대조구보다 모든 염류에서 낮았다. N 함량은 NaNO3, NH4Cl 및 대조구가 11% 내외로 가장 높았으나 Na 계열에서는 NaCl 및 NaHCO3 처리구가, Cl 계열에서는 KCI 처리구가 5.5~6.0% 내외로 낮았다. K 함량은 Cl 계열보다 Na 계열이 적었으며, 특히 NaCl과 Na2SO4 처리구에서 더욱 낮았다. Mg 및 Ca 함량은 대조구보다 낮았으며, NaCl과 KCl 처리에서 매우 낮아 Na 및 K 이온과 상당한 길항관계를 보였다 전반적으로 각 이온의 흡수는 KCl및 NaCl처리구에서 가장 낮은 경향이었다.